BSC 1020 – Reflection Paper Unit G
Evolution and its Processes
This unit covers the theory of evolution, its mechanisms, the modern synthesis of genetics and evolution, and classification of species. The first chapter describes the history involved in Darwin’s theory of evolution. It talks about the evidence that supports evolution like the fossil record, biogeography (geographical distribution of species), comparative anatomy, comparative embryology and molecular biology. These collections of evidence help explain how species evolve from a common ancestor with gradual changes over time due to natural selection.
Natural selection states that certain traits of an organism inside a population are better for adapting to the environment.
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Scientists focused on the gene pool of populations to account for the different traits being exhibited by members in the population. The different genes in the gene pool account for the variation in a population and mutations account for different alleles that an organism may have. When gene pools are changed by some sort of event or action, they are referred to as mechanisms of evolution. Genetic drift, the bottleneck effect, and gene flow are examples of mechanisms of evolution.
The second chapter of this unit talks about how species originate and how they are classified. Organisms are split into different species when their genotypes and phenotypes differ and they cannot breed an offspring capable of reproducing. Reproductive barriers and prezygotic barriers are two types are what prevent two different species from interbreeding. Speciation, the split of an organism into two different species over time, in different ways, allopatric speciation (geographical barrier), and sympatric speciation(reproductively isolated in same